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New VPP based
rule |
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At the conclusion of its
38th Annual General Meeting in Estoril, Portugal the Offshore
Racing Congress announced the formation of a new VPP-based
rating rule known as ORC International. This new rule will be
ready for use starting in January 2008 and will replace the
existing use of the International Measurement System for rating
purposes.
ORC International use the IMS platform of multiple modules from
measurement to scoring. However, the software for the most
important part - the Velocity Prediction Program (VPP) - has
been completely rewritten, with major functions reviewed and
recent submissions and research results implemented to produce a
more powerful and flexible software package.
Major technical factors that
have been given extra attention and adjustment include:
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A new Aero model with a
different evaluation of sail forces with heel angle
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Implementation of Code 0
sails
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A new Residuary
Resistance curve (part of the total resistance of the boat)
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A new Righting Moment
evaluation
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A new formulation for
effective draft of wings and bulb keels
This new rule represents the
culmination of work performed throughout this year by the ORC
Technical Committee, chaired by Alessandro Nazareth. Other ITC
members who have positively contributed include
Fietje Judel, who unfortunately retired from
the ITC, and Axel Monhaupt who for two decades has been the
Chief Engineer of the VPP formulations and algorithms, plus of
course former Chairman Manolo Ruiz de Elvira and Andy Claughton
who unfortunately were not able to be present in Estoril for the
finalization of the new Rule, but have had a major contribution
in its preparatory stages.
ORC will continue to offer
ORC Club as an inexpensive and simplified rule, having the same
VPP processor as ORC International, but with simpler measurement
procedures and automated web based forms already operational.
The ORC’s new rules, new certificates, and additional services
and products such as Stability Certificates, Performance
Packages, Sail Plans, and the like will be available on the ORC
website in early 2008, and the ORC
Offshore World and European Championships 2008 will be raced
under the ORC International rule.
Very soon ORC website will be completely restructured with new
rules, both measurement and rating, sample certificates, scoring
options as well as new features that will be available to every
ORC International certificate holder.
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Do I have
to go again through a complex measurement process both
ashore and afloat? |
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No, the new Rule can read all the data it
needs from the current IMS and ORC Club certificates data
formats.
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How are ratings changing
across the fleet? |
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The new ORC International
Rule and its Club sistership favour light boats with a high
stability or – to put it more accurately - it gives a
disadvantage to those who have a low stability and a low
Length/Volume ratio, as it is shown in the test run. It further
reduces the draft of keels having a bulb, giving therefore a
relative advantage to those configurations, and reduces the
length extension for immersed transoms in sunk condition. This
will be an advantage to some designs, especially to those
produced by J-Boats. However, the study on the L determination
continues to be a top priority in next year’s ITC agenda.
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I read some changes in the
sail areas formulations, do I have to re-measure any of my
sails? |
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If you had a certificate qualifying for an
asymmetric spinnaker measured before 2007, you would find only
the value for ASL as printed on the certificate, and so you will
have to read out or picture on your sail stamps the separate
values of SLU and SLE in order to obtain a marginal advantage in
rating.
Those who have already initialized a sail inventory in
2007 having already Asymmetric Luff and Leech recorded
separately will not require any further action, and the VPP will calculate
its results according to the new formulae without any further
action.
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Should I make my boat stiffer
or chop some more lead off the keel and stuff the
already-stuffed bilges? |
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You can try and test your
boat in this configuration in some winter championship race or
just training and comparing the polars with the ones of your
last knowledge. We all hope the new Rule will really encourage
stiffening boats.
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Is there
going to be new scoring software? |
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There is Windows - based
Velum NG available for purchase, or the traditional DOS -
based Altura program available for free through the ORC
website. No new product is scheduled for 2008.
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What is on
the ORC International certficate? |
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The first page is for
your ratings, including your theoretical boats speeds for
different wind ranges and strengths without going to any
calculations. You can just compare your real boats speeds
with those on certificate to know how much potential of your
boat you are using. The second page is reserved for the
measurements clearly divided in separate sections starting
from the rig, freeboards and inclining test, propeller, and
sails inventory together with measurement inventory. It is
important to note the certificate is self-producing in a way
that things that do not exist on the boat will not be
displayed (like mizzen, or water ballast, or canting keel
for boats without it).
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Has ORC Club also changed?
What's new? |
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The biggest improvement is
that the picture of the boat with rig and sail measurements will
be proportional to the real boat measurement and it will be much
easier to compare for example classic mast head cruiser/racer
with fractional rig races. There will be some other data
available like sail areas, sail limitation or spinnaker
configuration.
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Are there any changes in how the new VPP will handle
Asymmetrical Spinnakers? |
Yes, the Measurement Committee has
approved the following changes for asymmetrical
spinnakers:
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The formula ASL
= 0.6*SLU+0.4*SLE has been changed to a simpler
average: ASL = (SLU+SLE)/2.
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The requirement of a 5% difference
between luff and leech in Rule 816.2 a) has been
removed, considering as asymmetric all spinnakers
that don’t comply with the current symmetry
requirements.
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Asymmetric spinnakers are now
allowed to have AMG >= 0.65 ASF. An asymmetric
spinnaker with AMG between 0.75 and 0.65 ASF will
be considered a “Code Zero” and have a special
treatment in the VPP run.
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The default area
of asymmetric spinnakers will now be calculated
using the default values for ASL, AMG and ASF. The
default value for ASF has been modified as the
maximum of 1.6 TPS, 1.8 SPL, 1.8 J. The AMG default
is set as 0.75 ASF.
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Asymmetrical
spinnakers now have a different default area value
based on a different ratio to TPS, enabling boats to
be correctly rated if they have a smaller area than
their 2007 default.
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What are the changes for Jibs? |
Jib
and genoa area calculation (based on 4 girths + JH)
is simpler than the previous 2007 definition. It is:
JIB AREA = 0.1125*JL*(1.445*LPG+2*JGL+2*JGM+1.5*JGU+JGT+JH/2).
The formulation
for vertical center of effort of jibs will be
modified accordingly in VPP, and will allow
Measurers to compute the jib surface more easily
than with the current formulation, enabling them
also to write the area on sail stamps without the
need of a computer. A marginal amount of roach (max
1%) is also now allowed in Genoas (LPG > 110%).
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What are the changes for Mainsails? |
There are no measurement changes for
mainsails. However, the new VPP will use the concept of
maximum area and minimum weight calculated from default
measurements, and each certificate
will be run with a maximum area mainsail listed in the
inventory list, not with just the maximum girths of all
mainsails listed in the inventory list.
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Are Code Zero sails now allowed? |
Yes. Gennakers with
0.65*ASF<AMG<0.75*ASF are now allowed, and will be
counted in the boat's asymmetric spinnaker
inventory.
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What other changes were approved? |
There will be a Boom Depth
penalty assessed if BD>0.06*E. If BD exceeds
6% of E, then the
exceeding amount will be multiplied by E,
doubled, and added to the mainsail area.
There will no longer be a maximum or
minimum restriction on declared crew weight,
and the default crew weight for doublehanded
crews will be 170 kg.
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Are there related issues which remain unchanged? |
Yes. The maximum
number of sails on board will
remain unchanged, and there is no
difference in the mast weight and
fittings treatment.
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